we have a GitLab CE instance running on-premise with LDAP SSO configured (i.e. users are authenticated against our Active Directory).
We would like to use Mattermost now for notifications and such.
Is it possible to run Mattermost (which comes with GitLab Omnibus) on a GitLab CE instance so that users do not need a separate Mattermost account? I.e. users can login to Mattermost with their GitLab account, which is actually the Active Directory User?
Thanks in advance.